fix: set html/body background to black to prevent white bleed-through

The 3D canvas is position:fixed at 100vh, but the default white
html background was visible in areas where content extended beyond.

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via [Happy](https://happy.engineering)

Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

Author: 3 people

docs/projects/nthpartyfinder/index.html

@@ -48,13 +48,13 @@
 }
 
 *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
-html { scroll-behavior: smooth; }
+html { scroll-behavior: smooth; background: #000; }
 body {
   font-family: var(--font-body);
   font-size: 16px;
   line-height: 1.65;
   color: var(--text);
-  background: transparent;
+  background: #000;
   -webkit-font-smoothing: antialiased;
   padding-top: 68px;
 }